1. Field of the Invention
With respect to the classification of art as established in the United States Patent and Trademark Office this invention is found in the general Class entitled, "Measuring and Testing" (Class 73) and the subclass therein entitled, "turbine type with end supply and delivery" (subclass 231R). Also to be noted is the subclass entitled, "volume or rate of flow meter" (subclass 194R).
2. Description of the Prior Art
Turbine-type flow meters are generally well known and usually are constructed so as to have elongated housings in which a shaft is centrally mounted to carry the bladed turbine. On the shaft is mounted a propeller-type blade which is rotatable on this shaft. The rotational velocity of the shaft may be read or the turning blades themselves may be a function of the volume rate of the flow of the fluid. These blades, for example, as they rotate past a magnetic pickup cause a voltage or pulse to be generated each time a blade passes by the pickup. The number of pulses generated is, therefore, representative of the total volume of flow through the fluid passageway with the number of pulses per unit time being computed to indicate the volume rate of the fluid flow through the housing.
The magnetic pickup may either cause the pulses to be read and fed to a computer-type electronic apparatus to be computed as a rate of flow, or the magnetic pickup may be used to cause an electromotive force to be developed in a coil. This force is proportionate to the rate of movement of the blades so that a rate of flow can be read on a voltmeter-type instrument and the dial calibrated to indicate the rate of fluid flow. Many U.S. Patents are representative of this type of construction. For example, U.S. Pat. No. 3,101,615 to PAVONE as issued on Aug. 27, 1963 shows a magnetic pickup type of flow meter. Others of similar construction are seen in U.S. Pat. No. 2,975,635 to KINDLER as issued on Mar. 21, 1961; U.S. Pat. No. 3,177,711 to HAM as issued on Apr. 13, 1965 and U.S. Pat. No. 3,342,070 to WALCH as issued on Sept. 19, 1967.
It is to be particularly noted in these patents and in others that are known that the turbine blade is constructed so as to pass substantially close to the outer diameter of the flow meter passageway. In the reference, U.S. Pat. No. 3,771,363, which to the extent applicable is incorporated by reference into the present application, the probe carries on its end a small bladed turbine of plastic. This bladed turbine carries a ring-like magnet in its hub and in the present embodiment both ends of the turbine support shaft are mounted in a U-shaped member. This supporting end and bladed turbine are made as a replaceable and removable unit which enables a ready replacement to be made. It has been found that rough or careless handling may bend the stanchion member which carries the bladed turbine. This stanchion, as shown in U.S. Pat. No. 3,771,363, is welded to the probe housing. In the improvement, to be hereinafter more fully described, the bladed turbine is mounted in a U-shaped support as a removable and replaceable end member assembly.
In the present invention a probe carries the turbine blade on a shaft carried in a U-shaped support with the rotating blades maintained in a fixed relation to the magnetic pickup. This whole unit is carried as a probe which may readily be inserted into a pipe flange, support block, valve or the like and only requires that the turbine be positioned at the midpoint of the flow path in a pipe or conduit so as to give a reading on the velocity of the flow at this point in the stream.